1. Field of the Invention
The present invention relates to a thin film transistor substrate applied to a liquid crystal display device and a fabricating method thereof, and more particularly, to the thin film transistor substrate and a fabricating method thereof minimizing defects due to static electricity.
2. Description of the Related Art
Recently, a flat panel display device such as a liquid crystal display device, a plasma display panel, an organic light emitting diode, and an electrophoretic indication display has been developed to substitute for a CRT (cathode ray tube).
Generally, the flat panel display device comprises a display panel, and the display panel comprises the thin film transistor substrate 5 a thin film transistor formed on. As shown in FIG. 1, the thin film transistor substrate 5 is fabricated by steps of dividing a mother substrate 1 into a substrate area (a) and a peripheral area (b), forming a lot of layers on the substrate area (a) and patterning each layer into a specific shape, and cutting the mother substrate 1 in each substrate area (a).
A test process is carried out to test whether a defect occurs or not on the wire or layer of the substrate area (a) before dividing the mother substrate 1 into each substrate area (a). Among the test process, testing whether defects occur or not when a voltage applied to the wire or layer and the thin film transistor driven may be an MPS (mass production system) test. Electric defects are checked through the MPS (mass production system) test.
The following is an illustration of the MPS (mass production system) test referring to FIG. 1.
A lot of testing wires 15, 25, 35, 45, 55, 65 are provided on the peripheral area (b) for the MPS (mass production system) test. A lot of testing wires 15, 25, 35, 45, 55, 65 comprise a first test line 15 connected to an odd number gate wire (not shown), a second test line 25 connected to an even number gate wire (not shown), a fifth test line 55 connected to an odd number data wire (not shown), a sixth test line 65 connected to an even number data wire (not shown), a third test line 35 for testing whether a voltage is applied to the common voltage line (not shown) or not, and a fourth test line 45 for testing a short between substrate areas (a). The third test line 35 is connected to the common voltage line (not shown) and the fourth test line 45 is connecting between substrate areas (a). The thin film transistor substrate 5 shown in FIG. 1 is a dual gate type that a gate pad is provided on both sides of the substrate.
Each testing wire 15, 25, 35, 45, 55, 65 is connected to each pad 10, 20, 30, 40, 50, 60. The thin film transistor substrate 5 is tested whether electric defects occurs or not on the thin film transistor substrate 5 by applying a voltage to each pad 10, 20, 30, 40, 50, 60. After finishing the MPS (mass production system) test, the mother substrate 1 divided into each substrate area (a).
As described above, a lot of testing wires 15, 25, 35, 45, 55, 65 are provided on the thin film transistor substrate 5 complicatedly before dividing the mother substrate 1 into each substrate area (a). Thus, Static electricity occurred on the thin film transistor substrate 5 may go to each passage such as testing wires 15, 25, 35, 45, 55, 65, thereby minimizing defects due to static electricity.
However, there is no passage for static electricity that have occurred on the thin film transistor substrate 5 to go to because testing wires 15, 25, 35, 45, 55, 65 are cut when the mother substrate 1 is divided into each substrate areas (a). Thus, defects such as a short among the gate wire (not shown), the data wire (not shown), and the common voltage line (not shown) may occur. Even though static electricity prevention circuit is provided so as to prevent defects due to static electricity on the thin film transistor 5, static electricity prevention circuit is not enough for preventing defects due to static electricity because there is a lot of ways static electricity may be introduced. For example, while moving the thin film transistor film 5, the static electricity may be introduced into the thin film transistor film 5.